The rabbit retina is deprived of oxygen and/or glucose in vitro in an attempt to discover cell mechanisms of irreversible cell damage. Electron microscopic morphometry is employed to determine structural changes in cells and organelles and isotopically labelled mannitol and inulin to determine alterations in cell volume and permeability. Matters under current study include the possible role of cell swelling, altered permeability, and inorganic ions in irreversible damage. BIBLIOGRAPHIC REFERENCES: Shay, J.: Economy of effort in electron microscopy morphometry. Am. J. Pathol. 81:503-512, 1975. Shay, J.: Mitochondrial diameter in intact, ouabain poisoned or oxygen and glucose deprived retinal cells in vitro effect of calcium ion in medium. 1st Int. Cong. on Cell Biol., September 5-10, 1976. (Abstract)